a = {'x': 1, 'y': 2,  'z': 3}
b = {'w': 10,'x': 11, 'y': 2}

## 找相同的 key
print(a.keys() & b.keys())
print(a.items() & b.items())
print(a.keys() - b.keys())
print(b.keys() - a.keys())